It is proposed to study the effects of various carcinogenic and related DNA-binding drugs on the physical-chemical properties of mitochondrial genome and mitochondrial gene-products, namely mRNA and proteins. The proposed project is an extension of our preliminary observation that specific sequence alterations occur in mitochondrial DNA in chemically induced hepatomas. It is proposed to undertake a systematic analysis of rat liver mitochondrial DNA at various stages of neoplastic transformation using restriction endonuclease-cleavage. The proposed studies will include the verification of effects of 2-AAF, DEN, ethionine, DAB, and Aflatoxin, non-hepatic carcinogens as well as the non-carcinogenic DNA binding compounds. It is also intended to see if the alterations in DNA sequences are reflected in the mitochondrial mRNA species. Mitochondrial poly(A) containing and poly(A) lacking mRNAs will be purified from intramitochondrial polysomes and extensively studied using DNA-RNA hybridization, Rot estimations using cDNA and other analytical procedures. These studies are expected to show if any quantitative and/or qualitative changes occur in mt mRNAs and mt translation products including any sequence "additions" or "deletions" during chemically induced carcinogenesis. Further a detailed analysis of normal, hepatectomized, hyperplastic, regressed and neoplastic livers is expected to show if specific or random alterations in mt mRNA are due to a change in the information content of the mt genome or due to specific sequence alterations.